JPH1099373A - Disposable diaper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To soften the touch of a rear side sheet concerning a disposable diaper for which that rear side sheet is composed of two layers of inner and outer sheets at least. SOLUTION: A rear side sheet 3 of the disposable diaper is composed of an inside stretch sheet 3A and outside non-stretch nonwoven fabric 3B. The nonwoven fabric 3B is fixed on the extended sheet 3A at plural intermittently arranged sections 21. When the sheet 3A is shrunk, in a non-fixed area 28 between the sheet 3A and the nonwoven fabric 3B surrounded by the plural mutually adjacent fixed sections 21, gathers 22 floated from the sheet 3A are formed on the nonwoven fabric 3B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disposable diaper, and more particularly, to a diaper having a plurality of folds on a back sheet.

[0002]

2. Description of the Related Art It is well known that a back sheet of a disposable diaper is composed of a plastic film and a nonwoven fabric, and the plastic film is on the inside and the nonwoven fabric is on the outside, so that the diaper feels like a cloth. For example,
In the back sheet disclosed in Japanese Patent No. 122824, a stretchable plastic or rubber film and a stretchable nonwoven fabric are intermittently fixed, and these films and the nonwoven fabric are integrally stretched.

[0003]

The nonwoven fabric of the above-mentioned known backsheet sometimes loses its inherent flexibility by being fixed to a film, so that a diaper can be used as compared to a case where the nonwoven fabric is used alone. Softness of the skin tends to decrease. In addition, elastic non-woven fabrics and films
Since the cost is generally higher than that of a non-stretchable material, an increase in the cost of diapers due to the use of these materials cannot be avoided.

Accordingly, an object of the present invention is to provide a disposable diaper having a back sheet which has flexibility and elasticity and can be obtained at relatively low cost.

[0005]

In order to solve the above problems, the present invention is based on the premise that the top sheet on the skin contact side, the back sheet on the clothing contact side, and the interposition between these two sheets This is a disposable diaper comprising a liquid absorbing core.

[0006] On this premise, the present invention is characterized in that at least a part of the back sheet constitutes the inside of the back sheet, and is a stretchable sheet that can expand and contract in the width direction of the diaper. Constructing the outside of the back sheet, comprising a non-stretchable nonwoven fabric overlapping the stretchable sheet, the stretchable sheet and non-stretchable nonwoven fabric,
When the stretchable sheet is fixed to each other under the stretched state in the width direction of the stretchable sheet at a plurality of fixed portions intermittently arranged, and when the stretchable sheet is contracted from the stretched state, In a non-fixed area between the stretchable sheet and the non-stretchable nonwoven fabric defined by a plurality of the fixation sites adjacent to each other, the non-stretchable nonwoven fabric is separated from the stretchable sheet to form a fold. That
It is in.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the disposable diaper according to the present invention will be described below with reference to the accompanying drawings. In the description, the term "fixation" means that the abutting members are in a state in which they are substantially inseparable. Or in a substantially non-peelable state.

A diaper 1 shown in a partially broken perspective view in FIG.
Is a pants-type, in which the left and right width directions are contracted. The diaper 1 is constituted by a top sheet 2 serving as a contact side to the skin, a back sheet 3 serving as a contact side to clothing, and a liquid-absorbent core 4 interposed between these two sheets 2 and 3. The front and back sheets 2 and 3 overlap at a portion extending from the peripheral edge of the core 4 and are bonded by a hot melt adhesive (not shown). The diaper 1 has a front waistline region (front body) 6, a rear waistline region (rear body) 7, and a crotch region 8 located between the both regions 6,7. The front and rear waist regions 6 and 7 overlap each other at their left and right side edges in a palm-shape manner and are fixed at a portion 9 intermittently arranged vertically, forming a waist opening 11 and a pair of left and right leg openings 12. doing. At the edges of the openings 11 and 12 around the waist and the legs, the waist elastic members 13 extending in the respective circumferential directions are provided.
The leg elastic member 14 is located between the front and back sheets 2 and 3 and is adhered to at least one inner surface of the sheets 2 and 3 in a stretched state. The back sheet 3 is composed of an elastic inner sheet 3A and a non-elastic outer sheet 3B, and at least the front waist area 6 of the front and rear waist areas 6 and 7 is provided with both sheets 3A and 3B. The diaper 1 has a large number of portions 21 that are fixed to each other and a large number of pleats 22 that extend in the vertical direction of the diaper 1.

FIGS. 2 and 3 are plan views of the back sheet 3 at a portion surrounded by a virtual line 20 in FIG.
It is an III line end view. Inner sheet 3A of back sheet 3
Is a film of a thermoplastic synthetic resin elastomer, which has elasticity in the diaper width direction, and is in a contracted state in these figures. The outer sheet 3B is a non-stretchable spunbonded nonwoven fabric made of a thermoplastic synthetic fiber, and has a large number of pleats 22 extending generally in the vertical direction of the diaper 1. These inner and outer sheets 3A and 3B have at least one synthetic resin component melted and solidified at the fixing portion 21 to be integrated with each other. The fixing portions 21 are arranged close to each other on an imaginary line extending in a required direction. In FIG. 2, a number of parallel imaginary lines 26 having an upper right slope and a lower right imaginary line are shown. Are arranged on each of a number of parallel virtual lines 27 having a gradient of. The two adjacent lines 26 and the two intersecting and adjacent two lines 27 define a substantially rectangular area 28 in which the outer sheet 3B is separated from the inner sheet 3A by the inner sheet 3A. Floating, forming folds 22. The pleats 22 are irregularly shaped and the number of their stitches cannot be clearly counted.
In the end view of FIG. 3, there is a case where one top 29 is present in one area 28 and a case where two or more are present.

FIGS. 4 and 5 are a plan view and an end view when the back sheet 3 of FIGS. 2 and 3 is extended right and left. As for the back sheet 3, the inner sheet 3A is elastically extended and the outer sheet 3
It stops when the fold 22 of B is fully extended. The back sheet 3 at that time becomes substantially flat as shown, and the diaper 1 in FIG. 1 also becomes flat. In FIG. 4, the lines 26 and 27 drawn by the fixing portion 21 are, in other words, the lines 26 and 27 on which the fixing portion 21 is disposed are inclined by about 45 ° with respect to the horizontal direction. The back sheet 3 in the illustrated example can be manufactured based on FIGS. 4 and 5, and extends the original sheet of the stretchable sheet 3A in the width direction of the diaper 1 at a required magnification, and then expands the non-stretchable sheet. It is sufficient that the raw material of 3B is overlapped, and the raw materials of both sheets 3A and 3B are passed between hot embossing rolls to obtain a laminated sheet having fixed portions 21 of a required layout. This laminated sheet is a raw sheet of the back sheet 3, and when the sheet 3 </ b> A contracts, a fold 22 extending in a direction crossing the contraction direction appears. However, the manner in which the pleats 22 appear varies depending on the layout of the fixing portions 21.

In the diaper 1 having the back sheet 3 configured as described above, the back sheet 3 includes the inner and outer sheets 3A,
3B, the outer sheet 3B
Rises from the inner sheet 3A in the area 28,
Since the folds 22 can be formed, the folds 22 can provide the soft touch inherent to the nonwoven fabric.

FIG. 6 is a view similar to FIG. 3 showing another example of the back sheet 3 used in the present invention. The back sheet 3 includes an inner sheet 3A in addition to an inner sheet 3A made of a stretchable film and an outer sheet 3B made of a non-stretchable nonwoven fabric.
Third sheet 3 made of non-stretchable nonwoven fabric further inside A
C. The third sheet 3C is a nonwoven fabric such as a spunbonded nonwoven fabric containing thermoplastic synthetic fibers, like the outer sheet 3B, and is fixed to the inner sheet 3A at a fixing portion 21 for the inner and outer sheets 3A, 3B. In each section 28, the third sheet 3C forms a fold 31 which is spaced apart from the inner sheet 3A in the opposite direction (downward in the figure) to the outer sheet 3B, the fold 31 being the top 3
2 In the back sheet 3 configured as described above,
The apparent thickness when it is in the contracted state is the top 29
From the top to the top 32, which is much higher than when the back sheet 3 is in the stretched state. The back sheet 3 is flexible and has a high cushioning effect.

In the present invention, the inner sheet 3A constituting the back sheet 3 has an elastic recovery rate at 30 to 100% elongation in the range of 60 to 100% and a thickness of 0.01 to 100%.
It is preferable to use a stretchable film having a thickness of 0.1 mm at an elongation ratio within the elastic deformation range, and use a nonwoven fabric having a basis weight of 15 to 200 g / m ² for the outer sheet 3B and the third sheet 3C. The size and layout of the fixing portion 21
The diaper 1 may be formed so as not to substantially impair the elasticity of the inner sheet 3A and to form the folds 22 that give the diaper 1 sufficient flexibility. Therefore, the part 21
For example, the area can be 0.7 to 9 mm ² , and the distance between adjacent ones can be 1 to 5 mm. The lines 26 and 27 formed between the adjacent fixing portions 21 may be straight lines or curved lines. In the case of FIG. 4, the circular fixing portions 21 having a diameter of about 1.8 mm are arranged at a center interval of about 4 mm to form straight lines 26 and 27.
And each of the straight lines 27 has a parallel spacing of about 20 mm. Outer sheet 3B relative to inner sheet 3A
The fixing portion between the second sheet and the third sheet 3C may be different from each other in addition to the illustrated example. Also, the inner sheet 3A
Does not cover the entire diaper 1 as in FIG.
Part of the diaper 1, for example, the front waist region 6 and the rear waist region 7
May be located only on the left and right side edges of the diaper 1, whereby the diaper 1 may have the folds 22 formed only on that portion.

[0014]

According to the disposable diaper of the present invention, at least a part of the back sheet is constituted by an inner elastic sheet and an outer non-elastic non-woven fabric, and the elastic sheet is shrunk, so A large number of folds are formed that rise from the elastic sheet and protrude outward from the diaper. A diaper having a fold formed of such a nonwoven fabric on the outside has a soft touch inherent to the nonwoven fabric.

[Brief description of the drawings]

FIG. 1 is a partially broken perspective view of a disposable diaper.

FIG. 2 is a partial view of a back sheet.

FIG. 3 is an end view taken along line III-III of FIG. 2;

FIG. 4 is a partial plan view of the back sheet in an extended state.

FIG. 5 is a partial end view of the back sheet in an extended state.

FIG. 6 is an end view similar to FIG. 3, illustrating an example of a back sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Diaper 2 Top sheet 3 Back sheet 3A Elastic sheet (inner sheet) 3B Non-woven fabric (outer sheet) 3C 2nd non-woven fabric (third sheet) 4 Core 21 Fixed part 22 Fold 28 Non-fixed area (area) 31 Fold

Claims (5)

[Claims] 1. A disposable diaper comprising a top sheet on the skin contact side, a back sheet on the clothing contact side, and a liquid-absorbent core interposed between these sheets, wherein at least a part of the back sheet is Forming the inside of the back sheet, stretchable sheet that can expand and contract in the left-right width direction of the diaper, and forming the outside of the back sheet,
The stretchable sheet is composed of a non-stretchable nonwoven fabric overlapping the stretchable sheet, and the stretchable sheet and the non-stretchable nonwoven fabric are stretched in the width direction of the stretchable sheet at a plurality of intermittently arranged fixing portions. The stretchable sheet and the non-stretchable nonwoven fabric which are fixed to each other below and which are defined by surrounding the plurality of the fixing portions adjacent to each other when the stretchable sheet is contracted from the stretched state. Wherein the non-stretchable nonwoven fabric is separated from the stretchable sheet in a non-fixed area with the stretchable sheet to form a fold. 2. A second non-stretchable nonwoven fabric is fixed to the inside of the stretchable sheet at a number of intermittently fixed portions, and when the stretchable sheet is contracted,
The diaper according to claim 1, wherein the second non-stretchable nonwoven fabric also forms folds that are separated from the stretchable sheet. 3. The sheet according to claim 1, wherein at least one of the stretchable sheet and the non-stretchable nonwoven fabric contains a heat-fusible synthetic resin, and the melt-solidified resin forms a fixing portion between the sheet and the nonwoven fabric. Diapers. 4. At least one of the stretchable sheet, the non-stretchable nonwoven fabric, and the second non-stretchable nonwoven fabric contains a hot-melt synthetic resin, and the melted and solidified resin is bonded to the sheet and the two nonwoven fabrics. The diaper according to claim 2, wherein the diaper is formed. 5. The diaper according to claim 2, wherein a non-stretchable nonwoven fabric is fixed outside the same fixing portion of the stretchable sheet, and the second non-stretchable nonwoven fabric is fixed inside the stretchable sheet.